l have one 7500 15 inch mtx sub-woofer and 2 12 inch duel sub-woofers my question is will one 2000 watt amp be enough to power all three subs?

What u need to do is add up the RMS wattages of all the subs & see what it comes too. If its around 2000 watts then yes 2000 watts will be just fine. Also l do not recommend mixing subs but if u must u may want to be careful of how u wire them up. The subs would possibly have different RMS wattages & if u put the max wattage into the largest RMS wattage then ur smaller subs would get too much power. l would recommend using one amp for the MTX sub & a second amp for the 2 12'' subs. Also will that much power make sure u have a large enough power wire & u also may want a capacitor. A good rule of thumb is for each 1000 watts another capacitor or at least perform the ''big 3''
hope this helps.

it all depends on what kind of amp you got. But my question is why would you want to hook up an MTX sub wich is nice to a lol class duel